


The Sins of the Father

by Howlingdawn



Series: The Once and Future Family [1]
Category: Merlin (TV)
Genre: Alternate Universe - Canon Divergence, Angst and Hurt/Comfort, Canon-Typical Violence, Episode: s02e08 The Sins Of The Father, Family Feels, Gen, Hurt/Comfort, Protective Arthur Pendragon (Merlin)
Language: English
Status: In-Progress
Published: 2019-03-25
Updated: 2019-04-09
Packaged: 2019-12-07 19:12:21
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 12,151
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18239081
Author URL: https://archiveofourown.org/users/Howlingdawn/pseuds/Howlingdawn
Summary: When Arthur and Merlin are attacked, a sorceress shows up to save them. In exchange, she makes Arthur promise to fulfill a challenge, luring him in with the promise of learning about his mother. What they learn will change their lives forever.





	1. Chapter 1

**Author's Note:**

> This AU just hit me one day and it would NOT leave me alone (it's one of the few ideas I've ever had that could convince me to write a multi-chapter fic set during Uther's reign lol). I hope y'all enjoy it too!

"You _really_ are a clotpole, Merlin, you know that?"

Arthur rode just ahead of the servant, his hands clenched tightly around his horse's reins. Their horses _should_ have been loaded with the results of a day of hunting – hunting he had accomplished by a sheer miracle, given how many times Merlin scared off the prey – but _no_. They'd stopped at a tavern, where Merlin had blundered straight into the path of a very large, very angry man with lots of equally large, angry friends, and only Arthur trading over the entirety of their catch had kept him from being beaten to a pulp.

"I said I'm sorry."

"Sorry enough to spend an entire week hunting?"

He turned back at Merlin's desperate spluttering, grinning for the first time in two hours at the horror on Merlin's face. Arthur had no intention of following through on the comment – even he would get bored after a few solid days of it, even if it did come with Merlin falling flat on his face and making a complete fool of himself more than a few times – but he could get some enjoyment out of the bluff yet.

Or, he _would_ have gotten more enjoyment out of the bluff, had he not heard the familiar _twang_ of a crossbow firing. "Get dow-"

The arrow sank into Merlin's gut with a heavy _thud_. Time all but froze for a moment, Merlin's eyes widening as he looked down at the wound, touching it gingerly with fingers that came away glistening with fresh blood. Then his eyes rolled back into his head and he fell from his saddle, time slamming back to normal speed as his limp body hit the ground.

"Merlin!" Arthur cried, leaping off his own horse.

He'd hardly taken a step when bandits surged out of the trees, charging at him with a roar of battle cries. They easily outnumbered him ten to one, but with Merlin unconscious on the ground, running wasn't an option. He grabbed his crossbow off Merlin's horse instead, sticking a bolt in and shooting it into the hoard as fast as possible. One man went down and Arthur reloaded, managing to take out another two before the first man was upon him.

He dropped the crossbow and grabbed his sword just in the nick of time to block the first blow. The man delivering it was large and heavily muscled, and even successfully blocked, the strength of his blow made Arthur stumble back two costly steps, nearly stepping on Merlin's arm. He gritted his teeth and pushed back, shoving the man's sword away. In the split second he was unbalanced, Arthur killed him.

He had no reprieve before two more were on him. He sidestepped one blow, ducked beneath the second, and killed the nearest man. He kicked the second in the side of the knee, knocked his sword from his hand, and grabbed his arm and swung him around to take the stab aimed at Arthur's gut from a third man.

"Art-arthur-"

Arthur glanced back at the sound of Merlin's weak voice, horrified to spot more bandits running at them from the servant's other side. Merlin had one hand pressed down around the arrow still embedded in his stomach, the other raised as if that would do anything, shaking but ready to go down fighting.

As if Arthur would let that happen; knight or servant, he left no man behind. He shoved back the dead man he was still holding, knocking two of his buddies down with him, and grabbed Merlin's raised hand to drag him backwards. He groaned in agony at the unexpected movement, but Arthur ignored him, pulling him into the meager shelter of a pile of boulders. He planted himself between Merlin and the bandits and lifted his sword, ready to fight to the death.

He never had to.

Each and every bandit lurched to a halt, frozen in place. Then, as if yanked by an invisible hand, they flew backwards. Those who weren't knocked unconscious by the fall scrambled to their feet and fled.

"Who's there?" Arthur called, clutching his sword tighter. He'd almost rather be facing the bandits. They were normal men, and normal men he could fight, but a sorcerer who had just defeated them all with one blow? That would be… a _challenge_ , to say the least.

The person that emerged from the tree was an old woman, wavy white hair tucked beneath the hood of a worn black cloak. She raised her hands. "I mean you no harm."

"You are a sorceress. Your ways are forbidden here."

Slowly, she moved her hands to pull down her hood, offering a grandmotherly smile. "And yet, I saved your life. Surely that earns me some mercy?"

Arthur shifted, glancing at the bodies across the trail. "My father says-"

"Surely your father need not knowing everything?" she coaxed. "Such as how Camelot's soleheir risked his life to save a simple servant?"

Arthur glared. "How do you know who I am?"

She tapped her head. "I have my ways, young prince. Now, what is _your_ answer as to whether I should be shown mercy on behalf of my deeds?"

Arthur hesitated, glancing around. Skilled as he was, he had been severely outnumbered – without interference, he would've died fighting, or been forced to leave Merlin behind, and either way, his servant would be dead. She also had yet to show the slightest hint of aggression towards Arthur and Merlin. And with his own life no longer at risk, his next priority was getting Merlin back to Camelot as fast as possible.

So he lowered his sword, kneeling down beside Merlin. "I will grant you clemency this time. If I see you within Camelot's borders again, however, I make no guarantees."

He turned his attention to Merlin to allow her to slip away without giving away where she may be headed. Blood stained Merlin's shirt and his face had gone deathly pale. His eyelids flickered as he struggled to stay awake, the light in his eyes fading all too quickly for Arthur's liking. Arthur patted his cheek brusquely, and he winced away with a weak groan, but at least he looked slightly more awake.

"I can heal him."

Arthur jumped, looking up sharply to the sorceress standing only a few feet away. "I thought I told you to leave."

"You granted me clemency, sire, and in return I wish only to help. I have seen such a wound before – he will not survive the trip back to Camelot, no matter how fast you ride."

Arthur's heart seized at the words, making his hand slip down from Merlin's cheek to grip a fistful of his jacket. "But you mean to heal him with magic."

The sorceress nodded. "It is all that will save him now."

When Arthur still hesitated, she pressed on gently. "Magic is not the evil thing you have been raised to believe it is, Arthur Pendragon. It saved your life just now, did it not? And now it offers your friend there a chance at surviving this ambush."

"I won't know what you're doing. You could kill him instead."

She reached into her cloak and pulled out a beautiful bracelet, one made of silver with an intricate gold design on it. "This is a healing bracelet. I need only place a simple enchantment on it and place it on his wrist. There will be no trickery to the spell, I assure you."

Arthur felt the war within him. The war between everything he had been raised to believe, every law he vowed to uphold, and the fear he felt that Merlin would die. But if it was his beliefs that held him back, should he truly let them? It had been his belief once that he could never see a mere servant as his equal, and yet over the last nearly two years, he had fallen in love with one, and another had become his closest friend, and both were people he had disobeyed his father and risked his life to protect. If his belief that servants were unworthy of attention had been so badly wrong, could it be that not everything his father taught him was right?

He swallowed down his confusion, looking to Merlin. "It's your decision. I won't punish you or her if you agree."

Merlin blinked once, slowly, eyes wide as if he couldn't believe what he had just heard. Then he nodded, so Arthur turned back to the sorceress. "Do it."

She nodded, crouching stiffly on Merlin's other side. With a wrinkled hand, she picked up Merlin's hand, his limp fingers leaving thin trails of blood across her wrist. But then she stopped. "First, I wish to make a deal."

Arthur stiffened, stretching a protective hand over Merlin's chest. "What sort of deal?"

"Nothing harmful," the sorceress said.

"Can it not wait? He's _dying_ ," Arthur pushed, feeling Merlin's weak heartbeat beneath his palm. His breaths came in shallow pants now.

"I want assurance that you will not flee before you can choose to agree."

"Fine," Arthur ground out. "What do you propose?"

"A meeting," she said, "in two days' time. I will send a proxy to the castle later to discuss where. Once you have arrived, I will issue a challenge. You must accept it, no matter the cost. And," she tipped her head at Merlin, "you must bring him."

"What is the nature of this challenge?" Arthur asked warily.

"That is for me to decide and you to find out," she said sharply.

"I cannot walk blindly into such a task!"

"And yet, if you do not, your servant will die. Will you give me your word that you will come?"

"Arthur, no," Merlin protested.

But that was exactly what sealed the deal. Merlin's voice was so weak, barely audible even though Arthur crouched beside him, and while his endless chatter could be endlessly irritating, the few times Arthur had been left without it had become disconcerting at best. "I give you my word."

Merlin struggled, but even the old woman could hold his arm still now. She murmured an enchantment over the bracelet, and Arthur wavered as her eyes flared that sinister gold, but one glance at Merlin's blood smeared across her wrist stopped him from backing out. "Pull the arrow out."

Arthur braced one hand around the arrow and gripped it in his other fist. "Sorry, Merlin." He yanked, making Merlin arch his back in agony. The moment the arrow was clear, the sorceress slipped the bracelet on and he fell limp, panting heavily. Arthur leaned forward, peeling back his shirt, and nearly slumped in relief at the sight of the wound knitting itself back together. "It's work- Merlin?"

The servant's eyes rolled back into his head as he promptly passed out. "Merlin!"

"It's all right," the sorceress said, setting Merlin's hand down gently. "Magically healing such a wound takes a toll on the body. He will sleep for a while."

Arthur hovered his hand over Merlin's mouth, checking that he still breathed. "But he'll live?"

"He will live. I would bet my own life on it."

Arthur cast a threatening glare at her. "You may have to, if he dies before I can meet you for your challenge."

She smiled, using the boulder beside her to pull herself up. "Do remember to bring him when you come – I will wish to check on my handiwork."

She began to leave. "Wait," Arthur called after her.

"Hm?"

"Why would you help us? Why would you help _me_?"

"I knew your mother," she answered simply.

Arthur's heart skipped a beat. "You- you knew my mother? When? How? What-"

"All in due time, young Pendragon. All in due time."

She turned then, and it seemed as if she just disappeared into the shadows. Arthur half-rose, calling after her, but Merlin's vulnerability kept him rooted in place, unable to chase after the answers he had sought his entire life.

_Two days,_ Arthur told himself. _I can ask her in two days._

"For now," he said aloud, forcing himself to focus on the present, "let's get you back to Gaius."


	2. Chapter 2

**Notes for the Chapter:**

> I meant to have this up yesterday but I forgot, whoops. I do have this all written btw, so updates should be fairly regular

As the sky out the window began to take on the vibrant hues of sunset, Gaius checked on the meal he was cooking for dinner that night. Merlin inevitably returned from Arthur's hunting trips dirty, exhausted, grumpy, and starving, but a good stew would cheer him up. Provided, of course, he had time to eat it, but Arthur was typically a bit more lenient after a good hunt. Which, of course, depended on it being a good hunt, and with Merlin and only Merlin accompanying the prince, that was a bit of a longshot.

Ah well. Gaius would do what he could to care for the boy – God only knew exactly how many secrets and responsibilities rested on his shoulders, let alone how heavily they weighed on him. The least Gaius could do was make some dinner.

The door swung open. "Ah, Merlin, welcome- Merlin!"

Gwen led the way inside, holding the door open for Arthur. In his arms lay Merlin, unconscious, his shirt covered in blood. Gaius's heart quite literally stopped for a moment, fearing the worst as he followed them into Merlin's room. Gwen pulled the blanket back and Arthur set him down, backing off so Gaius could check on him.

Gaius's terror was quickly assuaged. Merlin's breaths and heart were strong and steady, and despite the blood, there was no wound he could find. "What happened?"

"We were attacked by bandits," Arthur answered. "Merlin was…" He trailed off then, looking at Gwen. "You should leave."

Gwen crossed her arms. "He's my friend, Arthur."

"And if you hear what happened, it could put you in danger should it ever be discovered," Arthur told her, his voice soft with concern. "Just… wait outside. Please."

Gwen hesitated, considering both young men, before dipping her head to Arthur. "Tell me how he is," she requested.

"Of course," Arthur promised.

She looked at Merlin once more before taking her leave, closing the door to Merlin's room behind her. As the lock clicked shut and her footsteps faded away, Gaius looked at the prince. "What happened?" he repeated.

Arthur took a deep breath, crossing his arms. "We were returning home – without any of our catch, I might add – when bandits attacked. One shot Merlin, and I was severely outnumbered. But… we were both saved. A sorceress took out the remaining bandits and healed his wound with that enchanted bracelet."

Gaius's eyes widened in shock. "You allowed this?"

"I…" Arthur shuffled his feet, uncharacteristically nervous, but given what he had evidently done, Gaius couldn't blame him. "I told Merlin that I would punish neither him nor the sorceress if he agreed, and he did."

"But sire, if your father were to find out-"

"I couldn't let him die!" Arthur snapped.

Gaius lowered his gaze, resting a hand on his ward's hair. "And I am grateful for that, sire."

"I'm sorry, I shouldn't have snapped at you," Arthur sighed, dropping his arms. He looked back at Merlin. "It was worth it, right? He'll live?"

Gaius checked his heartbeat again. "He is strong, and there is no wound to get infected. Yes, Arthur, he will live."

"Good," Arthur murmured. "I must tell Guinevere."

Gaius nodded absently, beginning to remove Merlin's jacket. It was then he spotted the bracelet Arthur had mentioned, and for the second time that night, his heart stopped. He picked up his ward's wrist, bringing it close so he might investigate the design on it. "Arthur?"

Arthur paused in the doorway. "Yes, Gaius?"

"This sorceress. What did she look like?"

"Um… She was an old woman. Long white hair, a bit of a hunchback. Why?"

_An old woman._ "Nothing. Go, you must be tired."

Arthur paused a moment longer before leaving, closing the door behind him. Only then did Gaius allow himself to react, leaning back and taking a shuddering breath. Only two people he knew of had genuine cause to wear a bracelet with that particular design on it, but neither were old. She must have come by it in a more morally dubious way. Because if she hadn't…

Gaius shook himself. She would not dare return to Camelot, and she certainly would not save a Pendragon. His concern had to be unfounded.

"Oh, Merlin," he sighed, returning to getting his blood-soaked clothing off, "you cause me stress in ways even you do not know."

\-----

Guinevere very nearly pounced on Arthur the moment he stepped into the hallway. "Is he all right?"

Arthur looked around carefully before taking her hand into his. "Merlin will be fine. If he's lucky, he'll be back to work bright and early tomorrow morning."

Guinevere squeezed his hand in relief. "I'm not sure he would consider that lucky."

Arthur laughed. "I have no doubt."

She nodded, her smile slowly fading. She stretched up onto her tiptoes to place a warm kiss on his cheek. "Whatever you did to save him, thank you. You're a good man, Arthur."

He tucked a loose lock of hair behind her ear. "I think I owe that to the person who taught me that servants are worth breaking a few rules for."

"You know you were risking your life for Merlin long before you fell in love with me."

But even as she pointed that out, Guinevere was smiling softly at him, leaning into his touch. She gazed up at him with those warm eyes, so full of love, and he found himself leaning in, his hand slipping to her waist to pull her against him, his eyes drifting shut as his lips neared hers…

Footsteps echoed down the corridor, making them spring apart. He cleared his throat, running a hand through his hair. "I should retire for the night. It's been a long day."

"And I should check on Morgana," she said, stepping back and sinking into a curtsy. "Good night, my lord."

"Good night, Guinevere."

She hurried away, glancing back once as she turned the corner. Arthur longed to follow, but he had already pushed too far, risked too much, trying to get a kiss in a public place. He turned around and trudged to his chambers, cursing himself somewhat. Being exposed could get Guinevere fired, banished, or perhaps even worse. He had to stop losing control like that, stop giving in to the heat of the moment. He should know better.

_Why can't we care about servants?_ he wondered. _What did they ever do but have the misfortune of not being born rich? Merlin didn't even think it was a misfortune, he simply didn't know any different. It's not his fault he's not a prince._

He sighed, giving himself a mental shake as he neared the door to his room. This was just how society worked. Nothing would change that.

A guard at the end of the hall stopped him, looking at his hair in concern. "Sire, are you all right?"

Arthur stopped, confused. "Why wouldn't I- Oh."

He glanced up, spotting a smear of red in his hair, and looked down to see Merlin's blood still on his hands. He winced internally, hoping he hadn't left any noticeable traces on Guinevere or her dress. "Yes, I'm fine, it's not my own blood. Find a servant to draw me a bath, would you?"

The guard dipped his head. "Yes, sire."

Arthur headed inside, hardly waiting for the door to close before kicking his boots off and beginning the process of undressing. He dumped it all in a pile to wait for Merlin to clean it, rubbing his hands mostly clean on his shirt. The blood was mostly dried – his light touches shouldn't have left any on Guinevere, he realized in relief. Wearing his trousers only, he found one of his older robes to wear while waiting for the bath. Then he settled at his desk to skim the reports left on it.

A knock sounded. "Come," he called.

He was expecting some bumbling gangly serving boy, but that was not what he got. No, in walked a woman, shrouded in a black cloak, but that could not hide her beauty. Golden curls tumbled out of her hood, framing deep brown eyes and a beautiful smile. He sat back, suddenly hyperaware of his state of undress. "Can I help you?"

She reached into her cloak and produced a small scroll. "My mistress requested that I give you this."

"And who is your mistress?" Arthur checked.

"I believe you encountered her earlier this evening, when she saved the lives of both you and your servant."

He held his hand out, and she crossed the room to place it in his palm. He unrolled it to find a map. "Is this where I am to meet her?"

The woman nodded. "In two days' time, with your servant at your side."

Arthur rolled the map back up, searching her eyes for her response. "Why so insistent upon Merlin's presence? The challenge was issued to me, not him."

She trailed a finger idly over a drawing of the Pendragon crest on one of his reports. "I am afraid I cannot answer that, but I do know that you will come to understand in due time."

Arthur leaned forward. "I agreed to possibly risk my life, not his. I want more information before I do so."

The woman shook her head. "I cannot answer," she repeated. Arthur took a breath, ready to push on, but she interrupted. "All I can say is that, if he does not accompany you, then you needn't bother showing up at all. And if you do not come, then you will never learn what my mistress knows about your mother."

Any retort Arthur might've made died on his lips. His hands came together of their own accord, his fingers going to twist his mother's ring around and around his finger. It was his only link to her, and he'd always longed for more. Here was his chance – he couldn't give that up. "I will leave the decision in his hands," he allowed.

She dipped her head. "I suppose that is all I can ask. Though I must admit, I am surprised you would give such consideration to a mere servant."

"I would give it to any person."

She smiled. "You are a good man indeed, then."

Another knocked sounded. "Just a minute," Arthur called. To the woman, he said, "You should leave now."

She curtsied, turning to obey. She paused beside the foot of his bed, and after a moment, looked at him over her shoulder. "I do hope you find the answers you have been seeking," she murmured.

"Thank you," Arthur said. She curtsied again and made it to the door before Arthur realized something. "Your mistress – I do not even know her name. Or yours, for that matter."

A beat. Then, "Morgause."

"…Which one of you is Morgause?"

She swept out the door without responding.

\-----

Gaius finished tucking Merlin in, now dressed in his pajamas, his dirty clothes set aside for Gaius to clean and mend while he rested. He set a glass of water and a piece of bread on his bedside table in case he was in need of either when he awoke, and with one last check of his steady heartbeat just to reassure himself, Gaius prepared to leave him be.

When he rose, he found a young woman standing in the doorway. "May I help you?"

She looked up, blonde curls swinging beneath her black hood. "Sorry! The door was open. I hope you don't mind, though in hindsight, my barging in here was rather rude."

"No harm done," Gaius assured her. "However, if we could take this into the main room, my ward here must rest."

"Ah. I would love to, but you see, the boy is why I'm here. My mistress gave him a healing bracelet earlier, and it's rather important to her. I was hoping I might have it back?"

"Of course," Gaius said, taking it from Merlin's wrist. He shifted slightly, mumbling a faint word or two at its loss, but settled down quickly. Gaius looked again at the worryingly familiar design. "If I may be so bold, I don't suppose you know how she came by it?"

The woman took it, settling it onto her own wrist. Her shoulders slumped the tiniest bit, as if its safe return to her brought her comfort. "I do not know for certain," she answered. "It may be a family heirloom, perhaps. She speaks of it fondly."

_And yet you are the one who seems fond of it._

Gaius studied her carefully. He was certain he had never seen her before, and yet… he felt that tug of familiarity. Perhaps there was something in her eyes… "Have we met before?"

"I was here once before," she admitted. "But I was a baby at the time. It is unlikely you would remember me if we had."

Gaius clasped his hands together, counting on the long sleeves to hide how his tight grip turned his knuckles white. "I see. Might I ask your name?"

"Morgause."

Gaius smiled tightly. "No, I do not believe we met."

"A shame. You seem like a kind man."

"You're very kind, Morgause."

She smiled. "I must take my leave of you, Gaius. My mistress wishes me to deliver this bracelet to Lady Morgana."

"Morgana? Why?" Gaius asked sharply.

"To ease her troubled nights," Morgause said. "The prince mentioned she has nightmares. No harm will come to her, I assure you."

Gaius pursed his lips. "Healing bracelets are forbidden."

"Then it'll just be our little secret, won't it?"

"I suppose," Gaius allowed grudgingly. He had no real proof that she was dangerous, and if she was who he suspected, he could not stop her. "Travel safely."

"Thank you."

She swept outside, and as she walked, her cloak shifted the tiniest bit, revealing expensive red fabric and shimmering jewels on her dress beneath. Gaius sat heavily, realizing she came from a family with money. Combine that with her familiarity, her story of being in Camelot as a baby, her fondness of the bracelet, and her decision to gift it to Morgana…

He feared what would come of this day.

**Notes for the Chapter:**

> Did I expect to get to write a soft Arwen moment in a fic about Merlin and Arthur? No, no I did not. But I love that I did


	3. Chapter 3

**Notes for the Chapter:**

> Welcome to where the point of this AU truly begins. I left y'all some foreshadowing last chapter, but this contains the first blatant mention of it. Enjoy!

Merlin licked his lips, feeling as if he emerged from a deep slumber. His mind was sluggish, but he realized he was in a bed. His bed. "Gaius?"

A few moments passed before a hand rested on his shoulder. "How are you feeling, my boy?"

He coaxed his eyes open, rubbing a heavy hand across them. "Tired."

"That is to be expected. Here, sit up a bit," he said, slipping a hand under Merlin's back. He obliged, a bit clumsily, but he managed it, and accepted the water Gaius handed him. It was wonderfully cool, the temperature helping wake him up. "Better?"

"Much," he said, wiping his mouth off on his sleeve.

"What do you remember?" Gaius asked.

Merlin scrunched his eyes shut, thinking back to the forest. "Arthur was ragging on me about losing all of our catch, and then… I got shot. Arthur tried to fight, but… there was a sorceress. And she…" His eyes flew open. "That _idiot_!"

Gaius furrowed his brows. "What?"

"That sorceress, she healed me, but she made Arthur agree to a challenge first." He threw his blanket off, tearing his shirt off to get dressed. "He doesn't even know what it is, the absolute _clotpole_. He hasn't left the castle, has he?"

"No, I don't believe so. Merlin-"

"If you're going to say I'm crazy for worrying, please don't bother."

"I wasn't."

Merlin paused, one arm in his blue shirt, and turned to see Gaius's worried expression. "What is it?"

Gaius sighed heavily, avoiding Merlin's gaze. "I hesitate to say all I know, for fear it would endanger you. But I will tell you that the old woman you saw sent someone claiming to be a servant of some sort, but she did not wear the clothes of a servant. And I fear I recognized her."

"Who is she?"

He shook his head. "I dare not say. But if I am correct, then she is a powerful enchantress. Be wary, Merlin. Both of you."

"An enchantress. Who wants Arthur to go to some mysterious challenge. That _can't_ be good."

"No," Gaius agreed grimly, "it cannot."

Merlin finished dressing quickly and hurried through the castle to Arthur's chambers. He didn't bother knocking, he just barged in and said, " _Tell me_ you're not _actually_ going through with that challenge."

Arthur looked up from the boy helping him dress. "Leave us, Johnny."

The boy bowed deeply and left, closing the door behind him.

"I'm glad you're feeling better and all, but you can't barge in here and speak to me that way," Arthur said, buckling his belt calmly.

"I can if I'm the reason you're being an idiot," Merlin shot back. "Arthur, why would you agree to something like that?"

"I'm sorry for saving your life, then," Arthur said drily. "I won't make that mistake again."

"No, I- _thank you_ for that," Merlin muttered. "I'm more concerned about whatever mess you just got yourself into."

Arthur sighed. "Merlin, your concern is touching, but I can handle myself."

"Arthur, she's an _enchantress_. A very powerful one."

Arthur picked up a scroll from his desk and tossed it to Merlin. "That's the map we'll use. Do you recognize the destination?"

Merlin unrolled it, looking at the route. It went into Cenred's kingdom, but bypassed Ealdor completely. "No."

"Hm."

Arthur came over and took it back. Merlin narrowed his eyes. "Why?"

He ran a hand through his hair. "Look, I'm leaving tonight regardless, so pack my bags. But Morgause seems _strangely_ insistent on you accompanying me on this quest, even though I alone agreed to the challenge. Much as it pains me to admit, you are right to worry, so I thought I would give you the option to bow out."

"Why don't we both just not go?"

"Because I gave her my word, Merlin. I won't renege on it."

"What if she makes you do something that's _worse_ than breaking your word?"

Arthur lowered his gaze, twisting his mother's ring. "I will risk it."

Merlin took a surprised step back. Arthur was stubborn about all things related to honor and nobility, but he also had more common sense than Merlin cared to admit. "Arthur," he said lowly, "what is this _really_ about?"

Arthur bit his lip, looking in that moment far more like a young boy than a grown prince. "She… she said she knew my mother."

_Oh._ "You never talk about her."

"Because there's not much to tell," he admitted quietly. "She died when I was barely three. I have a handful of vague memories, but they may very well be my imagination. And I can't ask my father, because he refuses to speak of her. Sometimes it feels as if she never existed at all."

Merlin sighed, leaning on the post of Arthur's bed. "I know how that feels."

Arthur looked at him, genuinely curious, so he elaborated. "My father left when I was very young, and my mother refuses to speak of him. I think I have a vague memory, but… I don't know."

"I feel as if I have this… sense of her. As if she's still part of me, even if I can't remember."

"Me too."

Arthur nodded slowly, considering Merlin with a new light in his eyes. "This is why I must meet Morgause. I need answers, Merlin, answers I can't get here. But I won't risk your life to do it if you don't want to."

"What happens if I don't go?"

"She said I would never find the answers I seek."

_Damn._ "Then I will go," he decided.

"This challenge of hers, it could involve you, Merlin," Arthur pointed out. "At the worst, it could be deadly for you. Are you sure?"

"Would you help me if I were seeking answers about my father?" Merlin asked.

Arthur didn't hesitate. "Of course."

"Then I will help you find your answers about your mother."

Arthur smiled.

\-----

Arthur picked at his lunch, watching the sunlight flash off his mother's ring. He'd worn it since the day he had grown big enough for it to fit, and even before then he had often put it on and pretended it was like getting a real hug from her. His father had never said anything about it. Even him giving Arthur the ring had just been him having a servant leave it on his bedside table in the middle of the night.

_Maybe it's time to try to make him talk._

Merlin came up with his jug. "Do you want more water?"

"No, thank you," Arthur said, pushing back from the table. "I think I'm done. Clear this lot up and then polish my armor."

"Where are you going?"

"To talk to my father."

He strode to the council dining chamber to find his father finishing off his own lunch. "Arthur!" he said. "What a pleasant surprise. To what do I owe this visit?"

Arthur clasped his hands behind his back. "I must leave Camelot for a while, Father."

"Oh? Why?"

"I…" _How to explain this without implicating magic…_ "I got into a spot of trouble with some bandits yesterday whilst hunting. Someone came by just in time to save my life, and in exchange, I agreed to a challenge."

Father furrowed his brows. "What sort of challenge?"

Arthur shrugged. "They did not say. But I gave my word."

"Well, clearly I am grateful that this person saved your life, but I cannot allow you to go through with this."

"I gave her my word."

"I do not care," Father said firmly. "You are the sole heir to Camelot's throne, and cannot go about risking your life in such a reckless way. They saved your life, you parted ways, and now it is done."

"As the heir to Camelot's throne, I cannot go about breaking my word either," Arthur protested.

"Better to break your word than leave your kingdom without its prince," Father said dismissively.

Arthur sat back on his heels, swallowing down his rage. This wasn't the real reason he had come – with or without approval, he would go to Morgause. "That is not the only reason I wish to go," he said carefully.

Father sat back. Evidently finished with his lunch, he donned the gloves he'd left on the table. "Oh? What is this other reason?"

"The person who saved me is named Morgause," Arthur said slowly, studying his father's face for any sort of recognition. He saw none, so he continued on. "She said she knew my mother."

Father went rigid. "I forbid you from seeing this woman ever again," he ordered sharply.

"But she said-"

"She is lying," Father said, rising and turning his back to Arthur. "I know no woman by the name of Morgause, and your mother never spoke of such a person."

"I did not sense she was lying."

"Then you sensed incorrectly!" Father snapped. One hand clutched the back of his seat, and Arthur wondered if the glove hid a white-knuckled grip. "You are to stay in Camelot."

"I want to know what she knows about my mother," Arthur pressed.

Father spun to glare at Arthur. Beneath the rage glinted a different emotion. Something… something like desperation. "She knows _nothing_!"

"And how do you know that?" Arthur shot back. "Just because Mother never told you of her does not mean she did not know her."

"I know because I know your mother!"

"Well, _I_ don't," Arthur hissed. "And I'm going to learn. From Morgause."

"Guards!" Father called, voice shaking ever so slightly. A pair of men swept inside. "Escort my son to his chambers. He is not to leave them."

"You're locking me in my room?" Arthur scoffed as they grabbed his arms.

"It is for your own protection!"

Arthur laughed, but it dripped with disbelieving rage rather than mirth. He let the guards turn him around and pull him out of the room before he shook them off, marching a step ahead of them. Based on his father's reaction to the news, he had the answer he needed: Morgause _did_ know something.

Something Arthur needed to know.


	4. Chapter 4

"Merlin," Gaius called, setting breakfast out the next day. "Merlin, if you don't hurry, you won't have time to eat."

Nothing.

_Odd. That normally gets him moving faster than a dragon._

"Merlin?" he called again, going to knock on the boy's door. _He isn't suffering complications, is he?_ "Merlin, are you all right?"

Concerned, he opened the door. Only to find a bed that hadn't been slept in.

_Oh no._

He searched the little room, searching for a note, for anything to hint at where Merlin had gone. He found nothing left behind, only missing clothes and supplies. Wherever he was, the boy had gone on a journey, and he didn't expect to return for several days. Merlin's words rang in his ears.

_That sorceress, she healed me, but she made Arthur agree to a challenge first._

Breakfast forgotten, Gaius hurried to Arthur's chambers. On the way, he crossed paths with Morgana. "Gaius?" she called. "Have you seen Arthur?"

He stopped, trying to appear calm. "No, I'm afraid not. Is there a message you would like me to pass along if I do?"

"No, nothing important," she said, lifting a hand to smooth her hair. "Thank you for the offer."

As she moved, Gaius spotted Morgause's bracelet resting on her wrist. She caught him looking and smiled. "Isn't it beautiful?"

"Indeed."

"A visitor gifted it to me. Morgause, she said her name was. I feel… I'd never met her before, but Gaius, I felt as if I knew her."

Gaius smiled. "I assure you, Lady Morgana, that you do not."

_You were, after all, born after your half-sister._

"Strange," she murmured, trailing a finger across the crest on the bracelet. "I will leave you to your work, Gaius."

"Have a nice day, Lady Morgana."

"And you as well."

Gaius dipped his head, waiting for her to turn the corner before resuming his own walk. The guards did not stop him from entering the prince's chambers, closing the door before he dared look around.

Just as in Merlin's room, the bed hadn't been slept in.

Both boys were gone. And, as usual, they had disappeared together. Likely to find Morgause.

"Oh no," Gaius breathed.

He conducted a hurried search, noting the same amount of missing clothes and supplies as in Merlin's room, but very nearly came up empty otherwise. It was by sheer chance he stopped at the right angle to see underneath the foot of Arthur's bed. There, on the floor, rested a single small scroll. He knelt stiffly to pick it up, finding a map inked onto the parchment.

He swallowed as he recognized their destination. He sank onto the edge of the bed, staring at the little map and all it meant.

_I will have to tell the king. I will have to tell him, and risk him making the connection between this secret and the one I have guarded closest of all._

\-----

Merlin had to admit that getting Arthur out of his room was a slight disaster. The rope had seemed like a brilliant idea at the time, and Arthur had certainly agreed, right up until Arthur went crashing to the ground because there wasn't enough of it. Granted, it was hilarious that the prince had landed in a pile of used straw and manure, but cleaning it off and getting some of it smeared on his own face in retaliation was not so fun.

But they had, at least, made it out of the city undetected. The sun now shone high overhead, warming the world as Arthur paused to check their map. "Are we getting close?"

"Of course not, Merlin," he said, putting it away. "We don't need to get there for another day. I wouldn't leave so soon if it would only take a few hours to get there."

Merlin pursed his lips. "I was just asking."

"Yes, well, ask fewer stupid questions."

"There's no such thing."

"Yes, there is, and you know it. You _embody_ it."

Merlin huffed.

Arthur, uncharacteristically, didn't drive his victory home.

Merlin leaned forward a bit, trying to see around Arthur's back. "Arthur?"

He shook himself. "What?" he grumbled.

"Something's bothering you."

"Nothing is bothering me, Merlin."

"Really? Because you've been too quiet."

"Just because _some_ of us don't prattle on endlessly about useless nonsense doesn't mean anything's wrong!"

"Then why get so defensive about it?" Merlin challenged.

Arthur jerked his horse to a halt, whipping around to glare at Merlin. "If you don't shut up, I'll gag you. Understood?"

Merlin set his jaw, falling silent. Arthur turned without a word and increased their pace, making it hard for Merlin to be heard over their horses' pounding hooves. Not that Merlin wanted to bother trying again. If Arthur wanted to be a clotpole about it, then he could suffer in silence.

\-----

It was nearly dark out before Gaius gathered the courage to approach the king. It had been a day of carefully picking out and dissecting every word he could possibly say, deciding how to admit to one truth while continuing to hide its twin. He had also debated the merits of even telling the king – the boys had a head start, and if they survived any potential confrontation, would discover the secret before any knights could stop them. He had to protect them from Morgause, but he also couldn't let anyone arrive if and when they were discovering the secret.

Ultimately, however, Morgause presented the immediate threat. Uther had to be told. If she turned on them, they would need the knights the king would send.

He paused outside the dining chamber, looking at the Pendragon crest on the guards' uniforms. _How will Arthur react? Will he protect him?_

_I must have faith in the prince,_ Gaius told himself firmly. _Part of him his been poisoned by Uther and his twisted ideals, but he is a good man. He will do the right thing._

Finally, he entered the room. "Sire," he greeted, bowing low.

"Gaius," Uther greeted. "What brings you here?"

"Nothing good, I'm afraid."

Uther shifted, straightening up and nudging aside his dinner plate. "What troubles you, physician?"

Gaius inhaled deeply. "What did Arthur tell you of the incident that occurred during his hunting trip?"

Uther stiffened. "He said that someone saved him from a bandit attack, issued a challenge, and mentioned that they knew his mother. I forbade him from going, of course. Why do you bring this up?"

_Do not mention Merlin. Do not mention Merlin._

"He came to see me after his attack for some light injuries," Gaius said. "And he mentioned that his savior was an old sorceress by the name of Morgause."

"A _sorceress_?" Uther hissed.

Gaius blinked, guessing that Arthur had left that detail out. Some relief flickered in his heart, immediately followed by guilt for being glad the prince was already lying to his father.

"Yes, sire. However, she left him a bracelet," Gaius continued. "Later, a young woman came to fetch the bracelet. She claimed to serve the older sorceress, but I am not so certain she was being entirely truthful."

"Explain."

"I recognized the design on the bracelet. It…" He lowered his head, hiding his expression from the king. "It bore the crest of the Great House of Gorlois. And there is only one woman besides Morgana who would have cause to wear such a bracelet. One who likely would have the ability to perform something called an aging spell to disguise herself as an old woman."

Uther's chair scraped harshly against the stone floor as he rose, pressing his palms flat to the table. "I was led to believe the child had died," he said lowly, his tone carrying the edge of a threat.

Gaius swallowed – there was no going back now. He forced the admission out. "The child was smuggled out of Camelot shortly after her birth. She survived, my lord."

" _How_?"

"I was the one to do it."

Uther paced forward. "Why? Why would you betray me?"

_Because she was a child, a child who had done nothing but simply be born with magic._ "I had sworn a binding oath to the Old Religion, sire. I believed it was my duty to protect the child."

"You should have told me sooner."

He lifted his head, finally looking Uther in the eye. "I break my silence now because I fear what Morgause may be up to."

Uther narrowed his eyes. "What do you mean?"

"She said she knew Arthur's mother."

"You believe she was telling the truth?" Uther asked sharply. If Gaius didn't know better, he'd have said it was panic in the king's tone.

"She is hardly older than Arthur, and was smuggled out of Camelot too soon besides," Gaius said. "But she would have been raised and trained by the High Priestesses. And they, sire, certainly did know of Ygraine. And her fate."

Uther sucked in a breath, turning his back to Gaius and bracing himself against the table. "Arthur is trapped in the citadel. He will not find out."

"I'm afraid you're wrong, sire."

Uther spun back. Slowly, Gaius held out the map. Uther snatched it up and unrolled it, eyes going wide. "Where did you find this?"

"In Arthur's room. What I did not find in there was the prince himself."

"Guards!" Uther yelled.

Immediately, the two men came inside. "Yes, sire?"

"Check to see if the prince is in his room. If not, take this map to Sir Leon, tell him to gather his finest knights, and set out at first light to hunt him down."

The guard who had spoken bowed as he took the map, and then both men scurried away.

"Does Morgana know?" Uther asked.

Gaius shook his head. "She remains unaware that she has a half-sister."

"Good. I will not have her loyalties divided."

_If Morgause does reveal to Arthur this secret, then I fear it may not be Morgana's loyalties you have to worry about._


	5. Chapter 5

**Notes for the Chapter:**

> SORRY I meant to have this up Friday, but real life interfered and I lost my chance until today. But it should be worth the wait!

The next morning, Arthur sat by the dying remains of their campfire. Merlin bustled about, preparing to resume their journey in stony silence. He had taken Arthur's snarled order to heart and hadn't said a word since. Arthur sighed, looking at the apple in his hand. It was their last one, and Merlin's favorite kind. He'd caught the servant looking longingly at them often enough.

"Merlin."

Merlin ignored him, focusing on saddling up his horse.

" _Mer_ lin."

Merlin finally stilled, his back to Arthur. "Yes, sire?" he ground out.

Arthur held the apple out. "Here."

Merlin glanced around. "Do you want me to pack it?"

"No, I want you to eat it."

He huffed, looking back to the horse. "Why would you want me to do that, sire?"

"Because I'm trying to apologize."

"You needn't bother, sire."

" _Mer_ lin," Arthur repeated. "You were right – there is something bothering me. And I took it out on you when I shouldn't have. I'm sorry."

Merlin turned around slowly, looking from the apple to Arthur's face. "You're actually apologizing?"

" _Yes_. Now hurry up and take this before I change my mind."

Merlin took it, eyeing Arthur for another moment before finally biting into it. "Thank you."

Arthur smiled half-heartedly at him. Merlin resumed his work with much less anger and a bit of his usual pep, munching away on the apple. Arthur's smile grew a bit more genuine, relaxing as some sense of normalcy returned. "You're not going to ask about my feelings again?"

"Depends," Merlin said through a mouthful of apple, "are you going to bite my head off again?"

_That's fair._ "No."

Merlin considered for a moment, then came over to sit beside Arthur. "What's bothering you, Arthur?"

Part of Arthur still wanted to back out, to stay silent and pack up and leave. But Merlin was the sappy type, and he had missed their banter and Merlin's surly retorts, the image of Merlin bleeding on the ground with an arrow in his gut still too fresh in Arthur's mind, so if this was the way to repair their friendship, he would do it. Plus, he'd held this inside his whole life – he needed to tell _someone_ , and no one would believe Merlin if he repeated it. "It's… it's about my mother."

Merlin crunched into the apple, and Arthur wondered if he made the comically loud noise deliberately. "What about her?"

"You said you barely knew your father. Do you ever… feel as if you've forgotten something about him? One of the few things you knew before he left?"

Merlin furrowed his brows. "No, I don't think so. Why?"

Arthur twisted his mother's ring. "I… I've had this feeling for most of my life. Remember how we said we had this sense of our missing parents?" At Merlin's nod, he continued. "I feel that for my mother, yes, but… I feel it for someone else too."

"Who?"

Arthur looked at him, wary of seeing any mockery, but there was only curiosity. "One of my memories of her… Merlin, I could've sworn she was pregnant."

"You have a sibling?" Merlin exclaimed.

"No! Yes. Maybe. I don't know! That's the problem. I have no memory of one, and certainly no one has ever mentioned one, but I've never been able to shake that feeling that I'm _missing_ someone. Someone for whom I have no name."

Merlin bit into the apple again. "You can't ask your father?"

Arthur huffed. "You should've seen the way he reacted to Morgause maybe knowing my mother. If I ever told him of my suspicions about a sibling… No, I can't."

"Gaius?"

"If it's true and it's a secret my father has ordered everyone to keep, then he wouldn't tell me anyway."

"You'd be surprised what Gaius would and wouldn't tell you," Merlin murmured. "If you don't find out today, you could ask him when we return to Camelot."

Arthur narrowed his eyes, wanting to ask what that meant.

A flash of armor in the trees cut him off.

"Merlin, down!" he ordered, springing to his feet. He ran to his horse and grabbed his sword, moving to meet the first knight that burst out of the trees. He parried the man's blow, pushing back and swinging his sword to twist his opponent's sword out of his hands, then felled him with a quick blow to the gut.

He spun on his heel, blocking a blow aimed at him from another knight sneaking up behind him. The knight recovered and swept low, forcing Arthur to jump backwards. He thrust forward again, and this time Arthur stumbled on the uneven ground. He slipped, grabbing a tree to stay upright, but it left him wide open for attack. Fortunately, the knight himself tripped, startled by his trousers suddenly falling down. Arthur recovered just before he did, killing him quickly.

"Arthur!"

Arthur spun, eyes widening as he saw two knights looming over Merlin, who was on the ground on his back, scrambling to get back. He grabbed the dagger from the belt of the man he'd just killed and flung it across the clearing. It sank into the back of one of the knights, knocking him forward. Arthur charged up behind the second, plunging his sword deep into the man's back. He yanked it out, the momentum sending the dead man crashing down over the remains of their fire.

On the ground, Merlin was trying to push the other dead knight off his chest. Arthur bent down to help, then pulled Merlin to his feet. "You all right?"

"Yeah," Merlin panted. "Thanks."

"Cenred's men," Arthur said, gesturing at the crest on their uniforms. "We need to move."

Merlin didn't respond, his shoulders drooping as he spotted something. "What is it?" Arthur asked.

He crouched to pick up what remained of his apple, now covered in dirt, leaves, and fresh blood. "It's ruined," he moaned.

Arthur rolled his eyes.

\-----

Gaius sat beside Uther in the council chambers, both men awaiting news from the search party for entirely different reasons. It took all of Gaius's willpower not to fidget or flee, terrified as he was of saying or doing the wrong thing. But that would be suspicious, and for the sake of the second child he had smuggled out of Camelot all those years ago, he could not reveal anything to Uther.

"How can there be no word yet?" Uther muttered. "It is nearly midday."

"And the prince had a full day's head start," Gaius pointed out. "Even pushing the horses, it will take time to catch up. Not to mention the added risk of sending such a large, armed party across the border into Cenred's kingdom."

"I do not care about the risk," Uther snapped. "You saw where that map was leading him, Gaius – a fortress of the Old Religion. Arthur's life is at stake. Camelot cannot lose the sole heir to her throne, nor I my only son."

An old, familiar rage worked its way through Gaius at those words. At all the lies and pain Uther's insistence on them as fact had caused. At all the pain they could yet cause. All of it utterly unnecessary.

"I shudder to think of what Morgause has planned for Arthur," Uther admitted.

"He is strong, sire," Gaius said. "I am sure he will return home safely."

"What do you believe she has planned for him?"

Gaius shrugged. "I cannot say with any certainty, sire. However, if she was using an aging spell as I believe, then she already had a chance to kill Arthur when the bandits attacked. Whatever her plans, I do believe the prince will survive."

"I hope you are right."

"As do we all."

Uther took a breath, looking at Gaius. "Do you believe she will reveal the true circumstances of Ygraine's death?"

"It is possible. Do _you_ believe she will?"

"I don't know," Uther said, leaning forward to put his face in his hands. "If Arthur finds out… would he ever forgive me?"

"Arthur loves you, sire," Gaius assured him. "Whatever his initial reaction may be, you and he must both remember that."

"He also loves his mother," Uther despaired. "And… he would have loved him."

Gaius thought back to one night many years ago – a lifetime ago for some. He remembered meeting a young couple, head-over-heels in love and more than ready to start a family. He remembered their joy as he gave them the means to do just that, and their determination to protect him. And he knew, even now, that it had been the best option.

"The right thing was done, sire," Gaius said firmly. "And Arthur is the rightful heir to Camelot's throne. Of that, I have no doubt."

Slowly, Uther nodded. "You're right, of course. That abomination has no place in Camelot."

_Abomination._

Gaius struggled to hide how he bristled at the word. Despite the circumstances of his birth, Arthur's younger brother was entirely the opposite.

\-----

Towards evening, Arthur and Merlin emerged from the forest where the trail should have ended. They merely wound up on the shoreline of a lake. It was a beautiful scene, yes, surrounded by trees, rippling gently beneath the bright blue sky, a waterfall at the other end adding a steady thundering to the birdsong around them. But one thing was missing: Morgause.

"Are you sure this is where the map was leading us?" Merlin asked, stopping beside him.

Arthur pulled it out. "Yes. There's nowhere beyond here."

Merlin leaned over to look at it. "I dunno, it kinda looks like it actually stops over there."

"Merlin, there's nothing but lake over there."

Merlin looked around. "What about the waterfall? It could be hiding something."

"Yes, a wall of solid rock."

"She's a sorceress, Arthur, it's hardly the best thing to be these days. She's probably concealed where she actually lives, and sticking it behind something that seems impenetrable would keep most people away."

Arthur blinked. "Merlin, that almost sounded smart."

"Yes, well, we do have to risk running into a wall of solid rock to test it."

"That makes much more sense coming from you." He sighed. "It's our best option, I suppose. Come on."

He urged his horse forward, plunging into the lake. The water reached well up his calves by the time he reached the waterfall, and he hesitated before it. The thunder was a roaring din now, and he had to yell for a chance to be heard. "You'd better be right about this, Merlin."

"I certainly hope so."

Taking a deep breath, Arthur moved forward. The water washed over him, pounding against his head and shoulders in an icy torrent. He tensed, expecting his horse to hit a wall or stop suddenly or react badly to nearly being forced into the rocks.

He passed smoothly through.

Soaking wet, he found himself in a small rock tunnel. He crossed it, his horse's hooves echoing against the stone, and emerged into a clearing at the foot of a large fortress. It loomed above him, parts of its blackened walls crumbling and covered in overgrown ivy. The daylight even seemed darker, as if the fortress carried its own aura of darkness.

"This place seems cheerful," Merlin commented.

Arthur glanced at him, guessing that his shiver had nothing to do with the cold water. "Relax, Merlin."

"But what if your challenge _is_ to kill me?"

"Do you really have so little faith in me, Merlin?"

"I- um- yes- no- I mean, yes, I trust you not to _willingly_ kill me, but this woman is a sorcerer. What if she enchants you to go through with the challenge no matter what?"

Arthur moved forward to search for a way in, hoping that would disguise his hesitation. Merlin's protest echoed in his head: _What if she makes you do something that's_ worse _than breaking your word?_ She was a sorceress, after all. But… "She hasn't done us any harm, Merlin. She saved both our lives – why would she kill us now?"

"Because you're a Pendragon and she's a sorceress?"

Arthur shook his head. "I don't know, Merlin. Her magic was used for good. What if…" He licked his lips, hardly able to believe he was about to say this. "What if magic isn't evil? What if it's only the users that are, while magic itself is simply a tool like my sword? A tool whose goodness depends on its wielder?"

Merlin fell silent for so long Arthur looked back to make sure he was still there. His eyes were wide, his expression stunned. "You… do you actually believe that?"

Arthur ran a hand through his hair. "I don't know."

They fell silent then, processing that particular revelation. A minute later, Arthur spotted a small doorway and stopped beside it. "Here's as good a place as any, I suppose. You ready?"

"As I'll ever be," Merlin muttered.

They dismounted, Arthur leading the way in. He clapped Merlin on the shoulder as he passed, a silent thanks for coming and assurance he would be safe. Merlin offered up a small smile, sticking close on his heels as they climbed a twisting staircase. They reached a small courtyard, at the center of which sat an axe embedded in a chopping block.

"Arthur…"

"I see it," he said, drawing his sword. "Morgause?"

"You came."

Across the courtyard, it was not the old sorceress, but the blonde young woman coming down the stairs to meet them. She wore a red dress accented with shimmering jewels, her chin held high even as her surprise showed in her eyes. "I was not certain you would."

"You," Arthur said, shifting slightly to better shield Merlin from her. She noticed, a smile twisting across her lips. "You lied to me."

"Simply prudence on my part," she said. "Had you reacted badly in the forest, I did not want you to know my true face."

"Then why show yourself at the castle?"

"I do have business besides you," she said with slight disdain. "But we are not here to discuss that."

"No," Arthur agreed. "What is the challenge you wish to set me?"

Morgause's twisted smile reappeared as she nodded at the axe. "Kill your servant."


	6. Chapter 6

Arthur grabbed Merlin's wrist, holding him close while he pointed his sword at Morgause. "I will not."

"You gave me your word, Arthur Pendragon," she said sharply.

"I gave you my word, breaking every law I've sworn to uphold in the process, to _save_ his life," Arthur retorted. "Why would _I_ take it now?"

"Because you want to learn about your mother."

Arthur started pushing Merlin back the way they'd come in. "Not at the cost of Merlin's life."

Morgause's eyes flashed. A gate came screeching out of the stone, crashing down in a burst of sparks. Arthur and Merlin jumped back, spinning for another exit, but she closed that off as well. "This is your only chance, Arthur. If you do not kill your servant, you will never know what I know about Ygraine."

Arthur clutched his sword tighter, feeling Merlin's pulse pounding against his palm, feeling his mother's ring digging into his finger. He'd longed for this knowledge all his life, but he couldn't give up Merlin to do it. "Then I'll never know. I will not trade Merlin's life for that knowledge."

Morgause jerked her chin. The axe flew out of the chopping block, barreling straight for Merlin. Arthur swung his sword up. The axe hit it, the powerful blow reverberating through the blade and up Arthur's arms. He gritted his teeth and dug his heels in, pushing back against it. With a growl of effort, he shoved it away.

When it tumbled back through the air, Morgause softened, smiling. She held up her hand and it stopped midair. With a wave, she returned it safely to the chopping block, and the gates retracted quietly. "Good," she said.

Arthur narrowed his eyes warily. "What does that mean?"

"It means that you have proven you are a good man, and are worthy of the knowledge I possess."

"…You don't want me to hurt Merlin?"

She shook her head. "I do not."

Slowly, Arthur lowered his sword. Behind him, Merlin let out a breath of relief, slumping back against the wall. To his credit, he hadn't flinched through the whole thing, trusting Arthur to protect him. He let out a breath of his own, relieved that he hadn't betrayed that trust.

"Come," Morgause said, gesturing towards a pathway.

"Why can't you tell me here?"

"Because it is easier to show you. Come," she repeated. "I promise no further harm will come to either one of you."

Arthur started to follow, but Merlin hooked a hand around his elbow, making him turn around. "Are you sure this is a good idea?" he asked.

"Merlin, we've been through this."

"I know, I do, but- can't you just ask Gaius?"

"Look, I know you have faith in him, and so do I, but the fact remains that he's had my whole life to tell me and he's said nothing," Arthur said. "This, Merlin, is the best opportunity I've ever had to learn about my mother and my sibling. I need to take it. But if you're uncomfortable with using magic, then you can go."

Merlin huffed a wry laugh. "You're an idiot, you know that?"

Arthur furrowed his brows. "What does that mean?"

"It means I'm staying, Arthur," he said. "I always do, don't I?"

Arthur thought back over the last couple years, realizing that, for the most part, it was true. No other servant he knew, save Guinevere, followed their master on any and every mission even when told to stay behind. "Hm. Maybe you do have a spine."

"Was that a compliment?"

"Don't be stupid."

After a moment of laughter, Merlin sobered. "I do want to make certain that you're certain, though. She's a sorceress, Arthur, the very thing your father has been fighting against since you were a boy. Are you really comfortable going against him like this?"

"Remember what I said earlier, about wondering if magic was a tool just like any sword?"

"Seeing as it was only a few minutes ago, yes, I remember that quite clearly."

"No need for the sarcasm, _Mer_ lin," Arthur said. " _As_ I was saying, maybe this is what proves me right or wrong. If she shows me what I want to know, after what she did to save our lives, then I'm right. If she tries to attack us, well, my father is right. And if I'm right… I have some thinking to do."

Merlin stared at him as if he'd just grown a second head.

"I know," Arthur muttered. "I know it's insane. It's treason. But I can't be king and uphold the law if I have these doubts. I need to know."

"Prince Arthur," Morgause called.

But Arthur needed a minute, just one more reassurance. "Am I insane?" he asked. "Is it so crazy to wonder these things?"

Merlin shook his head, perhaps a bit more emphatically than the situation called for. "No, it's not. A good king must form his own opinions and rule according to his heart, no one else's."

Arthur let out a breath he hadn't realized he was holding. "You're right."

"Have you changed your mind, Prince Arthur?"

He turned to see Morgause peeking around the corner. "No," he said, confident in his decision now. "I haven't."

Arthur and Merlin followed her into a second area. This one was a bit larger, the walls mostly covered in thick ivy. There was a table at one end, and upon it Morgause began to arrange and light dozens of candles in a very specific order. Arthur waited beside Merlin, arms crossed tightly to avoid fidgeting, as the sun sank below the horizon, casting them into a darkness lit only by candlelight.

Finally, she turned, holding her hand out to Arthur. "Come."

With one last glance at Merlin, who nodded him forward, Arthur took it, letting her guide him forward and turn him so he faced empty space. "Close your eyes."

Arthur closed his eyes.

She began to speak, her words strange, and the hairs on the back of Arthur's neck rose at the power that seeped through the air as she spoke. A warm breeze kicked up, rustling the leaves around them. When it died down, a woman spoke.

"Arthur?"

His eyes flew open. In front of him, mere paces away, stood a petite woman with raven black hair, kind blue eyes going wide at the sight of him. "Arthur!" she cried, beginning to run forward. She flung her arms around him, pulling him close, one hand going to tenderly stroke his hair. "Oh, my son."

A lump in Arthur's throat choked off his words, not that he knew what to say. He hugged her in return, burying his face in her shoulder. He clung to her, never wanting the moment to end. He felt safer than he ever had in his father's arms, more loved even than when he was in Guinevere's arms. For the first time since he was three, he was _home_. "Mother," he breathed.

She pulled back all too soon. "Let me look at you," she said, cupping his cheeks in her hands. She smiled. "If I didn't know better, I'd say you look like me."

Arthur's joy died in a flash. "What?"

Mother furrowed her brows. "You sound confused."

"Because I am," he said slowly. "Why wouldn't I look like you?"

She tilted her head, running a soft thumb along his cheekbone. "Arthur… you were adopted."

Arthur choked now for an entirely different reason. "I- I was _what_?"

"You did not know?"

" _Know_? No! I'm- I'm a Pendragon."

"You are," she said firmly. "You are a Pendragon in every way that counts. Do not forget that. Ever."

Arthur swallowed, but he couldn't argue, not against the first order his mother had given him since he was three. "I-I won't."

"Good," she murmured. "Now, where is your brother? Is he safe?"

"Brother?" Arthur repeated. "So it's true? I have a sibling?"

Mother stared up at him, horror growing in her eyes. "Of course you do, Arthur. Emrys is the last gift I ever left you."

"Emrys?" Arthur echoed. "His name is Emrys?"

"Yes," she said slowly, looking around. "He…" A smile broke across her face. "You're pulling my leg."

She left him, and Arthur's world shattered.

Arthur's mother went to cup Merlin's face in her hands, smiling up at him. "I am so glad you survived, Emrys."

Merlin stared down at her, face white with shock. "You… you're what?"

Mother faltered, taking a step back, glancing between prince and servant. "You… you truly do not know. Neither of you."

"Know _what_?" Arthur pressed desperately.

Mother buried her face in her hands. "Uther, what have you done?" she whispered. "What did you do to our boys?"

" _Mother_ ," Arthur very nearly whined.

She took a deep, shuddering breath. "Come here," she said, holding her hands out, one to each boy. Arthur took hold of her without hesitating, but Merlin took an endless moment to finally slip his trembling hand into hers. She squeezed tight, drawing herself up to look strong, before speaking again.

"Shortly after Uther and I married, we discovered I was barren. So when I found you, Arthur, abandoned on the side of the road, I believed you to be the answer to our prayers. I took you in without hesitation, and I loved you as my own for the rest of my days. But Uther… he was concerned. Should it be discovered that you did not carry his blood in your veins, he wanted a backup plan to ensure his family would still sit upon the throne for generations to come.

"He betrayed me. He went behind my back and made a deal with the High Priestess to impregnate me. But in order to create a life, one must be taken. I do not know for certain if he knew that he bargained mine, but shortly after Emrys was born, I died. I had only time to name him."

Arthur couldn't breathe. All his life, he had been lied to. By his own father.

Merlin spoke, his voice tiny and shaking. "I… I killed you?"

" _No_ ," Mother insisted. She released Arthur to take both of Merlin's hands into hers. "Uther killed me. You, Emrys, you are not to blame for anything. I only got to hold you for a moment, but it was one of the most precious moments of my life. I would not trade your life for anything."

Merlin's lip trembled, his cheeks coated in tears, and Arthur knew he looked the same. Mother swept them into a hug, clutching them both close. "I love you both," she said fiercely, pressing kisses to both of their cheeks. "I love you both with all my heart."

Slowly, Arthur found himself hugging not only her, but Merlin.

_My mother._

_My brother._

Merlin's arm came up to wrap around him too, and against all the odds, it felt… right.

"I have only a few moments left," she said, pulling back just enough to look at them. "Emrys, sweetheart, if you do not know who you are, what do they call you?"

"M-merlin."

Mother smiled. "Merlin," she repeated softly. "Merlin and Arthur. Yes, I think it fits. Arthur and Merlin Pendragon."

The warm breeze swept by again, and when it cleared, she was gone.

"Mother!" Arthur cried, reaching for the empty air where she had been. He turned, frantically looking for Morgause. "Bring her back!"

"I cannot," she said sadly. "Once the doorway is closed, it is closed forever. For what it's worth, I am truly sorry that you two learned of your true heritage in this way. I can… only imagine how it must feel to discover your father is responsible for both your mother's death, and the two of you growing up apart."

Arthur sniffed, looking back at Merlin. He was still wrapped in Arthur's arm, still crying as he stared at the spot where his- where _their_ mother had disappeared. _I could've had a life with him,_ Arthur realized. _I wouldn't have been alone in my destiny all these years. I… we… we could've…_

He couldn't even begin to list all the things they could have done if they had never been separated.

Morgause was still speaking. "It is… an unforgivable betrayal."

Something in her tone tugged at Arthur, something suspicious, but he couldn't bring himself to care at the moment.

_I have a brother._

**Notes for the Chapter:**

> AND NOW YOU KNOW. I would die for this AU tbh, it just adds an extra something when I watch the eps and pretend this is canon. I just. Love it. So much.


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